arch/arm/include/asm/dma-mapping.h - maze/linux - Git at Google

 #ifndef ASMARM_DMA_MAPPING_H
 #define ASMARM_DMA_MAPPING_H

 #ifdef __KERNEL__

 #include <linux/mm_types.h>
 #include <linux/scatterlist.h>
 #include <linux/dma-debug.h>

 #include <asm-generic/dma-coherent.h>
 #include <asm/memory.h>

 #ifdef __arch_page_to_dma
 #error Please update to __arch_pfn_to_dma
 #endif

 /*
  * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
  * functions used internally by the DMA-mapping API to provide DMA
  * addresses. They must not be used by drivers.
  */
 #ifndef __arch_pfn_to_dma
 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
 {
 	return (dma_addr_t)__pfn_to_bus(pfn);
 }

 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
 {
 	return __bus_to_pfn(addr);
 }

 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
 {
 	return (void *)__bus_to_virt(addr);
 }

 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
 {
 	return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
 }
 #else
 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
 {
 	return __arch_pfn_to_dma(dev, pfn);
 }

 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
 {
 	return __arch_dma_to_pfn(dev, addr);
 }

 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
 {
 	return __arch_dma_to_virt(dev, addr);
 }

 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
 {
 	return __arch_virt_to_dma(dev, addr);
 }
 #endif

 /*
  * The DMA API is built upon the notion of "buffer ownership".  A buffer
  * is either exclusively owned by the CPU (and therefore may be accessed
  * by it) or exclusively owned by the DMA device.  These helper functions
  * represent the transitions between these two ownership states.
  *
  * Note, however, that on later ARMs, this notion does not work due to
  * speculative prefetches.  We model our approach on the assumption that
  * the CPU does do speculative prefetches, which means we clean caches
  * before transfers and delay cache invalidation until transfer completion.
  *
  * Private support functions: these are not part of the API and are
  * liable to change.  Drivers must not use these.
  */
 static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size,
 	enum dma_data_direction dir)
 {
 	extern void ___dma_single_cpu_to_dev(const void *, size_t,
 		enum dma_data_direction);

 	if (!arch_is_coherent())
 		___dma_single_cpu_to_dev(kaddr, size, dir);
 }

 static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size,
 	enum dma_data_direction dir)
 {
 	extern void ___dma_single_dev_to_cpu(const void *, size_t,
 		enum dma_data_direction);

 	if (!arch_is_coherent())
 		___dma_single_dev_to_cpu(kaddr, size, dir);
 }

 static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
 	size_t size, enum dma_data_direction dir)
 {
 	extern void ___dma_page_cpu_to_dev(struct page *, unsigned long,
 		size_t, enum dma_data_direction);

 	if (!arch_is_coherent())
 		___dma_page_cpu_to_dev(page, off, size, dir);
 }

 static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
 	size_t size, enum dma_data_direction dir)
 {
 	extern void ___dma_page_dev_to_cpu(struct page *, unsigned long,
 		size_t, enum dma_data_direction);

 	if (!arch_is_coherent())
 		___dma_page_dev_to_cpu(page, off, size, dir);
 }

 extern int dma_supported(struct device *, u64);
 extern int dma_set_mask(struct device *, u64);

 /*
  * DMA errors are defined by all-bits-set in the DMA address.
  */
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	return dma_addr == ~0;
 }

 /*
  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
  * function so drivers using this API are highlighted with build warnings.
  */
 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
 		dma_addr_t *handle, gfp_t gfp)
 {
 	return NULL;
 }

 static inline void dma_free_noncoherent(struct device *dev, size_t size,
 		void *cpu_addr, dma_addr_t handle)
 {
 }

 /**
  * dma_alloc_coherent - allocate consistent memory for DMA
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @size: required memory size
  * @handle: bus-specific DMA address
  *
  * Allocate some uncached, unbuffered memory for a device for
  * performing DMA.  This function allocates pages, and will
  * return the CPU-viewed address, and sets @handle to be the
  * device-viewed address.
  */
 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);

 /**
  * dma_free_coherent - free memory allocated by dma_alloc_coherent
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @size: size of memory originally requested in dma_alloc_coherent
  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
  * @handle: device-view address returned from dma_alloc_coherent
  *
  * Free (and unmap) a DMA buffer previously allocated by
  * dma_alloc_coherent().
  *
  * References to memory and mappings associated with cpu_addr/handle
  * during and after this call executing are illegal.
  */
 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);

 /**
  * dma_mmap_coherent - map a coherent DMA allocation into user space
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @vma: vm_area_struct describing requested user mapping
  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
  * @handle: device-view address returned from dma_alloc_coherent
  * @size: size of memory originally requested in dma_alloc_coherent
  *
  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
  * into user space.  The coherent DMA buffer must not be freed by the
  * driver until the user space mapping has been released.
  */
 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
 		void *, dma_addr_t, size_t);


 /**
  * dma_alloc_writecombine - allocate writecombining memory for DMA
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @size: required memory size
  * @handle: bus-specific DMA address
  *
  * Allocate some uncached, buffered memory for a device for
  * performing DMA.  This function allocates pages, and will
  * return the CPU-viewed address, and sets @handle to be the
  * device-viewed address.
  */
 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
 		gfp_t);

 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 	dma_free_coherent(dev,size,cpu_addr,handle)

 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
 		void *, dma_addr_t, size_t);

 /*
  * This can be called during boot to increase the size of the consistent
  * DMA region above it's default value of 2MB. It must be called before the
  * memory allocator is initialised, i.e. before any core_initcall.
  */
 extern void __init init_consistent_dma_size(unsigned long size);


 #ifdef CONFIG_DMABOUNCE
 /*
  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
  * and utilize bounce buffers as needed to work around limited DMA windows.
  *
  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
  *
  * The following are helper functions used by the dmabounce subystem
  *
  */

 /**
  * dmabounce_register_dev
  *
  * @dev: valid struct device pointer
  * @small_buf_size: size of buffers to use with small buffer pool
  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
  * @needs_bounce_fn: called to determine whether buffer needs bouncing
  *
  * This function should be called by low-level platform code to register
  * a device as requireing DMA buffer bouncing. The function will allocate
  * appropriate DMA pools for the device.
  */
 extern int dmabounce_register_dev(struct device *, unsigned long,
 		unsigned long, int (*)(struct device *, dma_addr_t, size_t));

 /**
  * dmabounce_unregister_dev
  *
  * @dev: valid struct device pointer
  *
  * This function should be called by low-level platform code when device
  * that was previously registered with dmabounce_register_dev is removed
  * from the system.
  *
  */
 extern void dmabounce_unregister_dev(struct device *);

 /*
  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
  */
 extern dma_addr_t __dma_map_page(struct device *, struct page *,
 		unsigned long, size_t, enum dma_data_direction);
 extern void __dma_unmap_page(struct device *, dma_addr_t, size_t,
 		enum dma_data_direction);

 /*
  * Private functions
  */
 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
 		size_t, enum dma_data_direction);
 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
 		size_t, enum dma_data_direction);
 #else
 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
 	unsigned long offset, size_t size, enum dma_data_direction dir)
 {
 	return 1;
 }

 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
 	unsigned long offset, size_t size, enum dma_data_direction dir)
 {
 	return 1;
 }


 static inline dma_addr_t __dma_map_page(struct device *dev, struct page *page,
 	     unsigned long offset, size_t size, enum dma_data_direction dir)
 {
 	__dma_page_cpu_to_dev(page, offset, size, dir);
 	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
 }

 static inline void __dma_unmap_page(struct device *dev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir)
 {
 	__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
 		handle & ~PAGE_MASK, size, dir);
 }
 #endif /* CONFIG_DMABOUNCE */

 /**
  * dma_map_single - map a single buffer for streaming DMA
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @cpu_addr: CPU direct mapped address of buffer
  * @size: size of buffer to map
  * @dir: DMA transfer direction
  *
  * Ensure that any data held in the cache is appropriately discarded
  * or written back.
  *
  * The device owns this memory once this call has completed.  The CPU
  * can regain ownership by calling dma_unmap_single() or
  * dma_sync_single_for_cpu().
  */
 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
 		size_t size, enum dma_data_direction dir)
 {
 	unsigned long offset;
 	struct page *page;
 	dma_addr_t addr;

 	BUG_ON(!virt_addr_valid(cpu_addr));
 	BUG_ON(!virt_addr_valid(cpu_addr + size - 1));
 	BUG_ON(!valid_dma_direction(dir));

 	page = virt_to_page(cpu_addr);
 	offset = (unsigned long)cpu_addr & ~PAGE_MASK;
 	addr = __dma_map_page(dev, page, offset, size, dir);
 	debug_dma_map_page(dev, page, offset, size, dir, addr, true);

 	return addr;
 }

 /**
  * dma_map_page - map a portion of a page for streaming DMA
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @page: page that buffer resides in
  * @offset: offset into page for start of buffer
  * @size: size of buffer to map
  * @dir: DMA transfer direction
  *
  * Ensure that any data held in the cache is appropriately discarded
  * or written back.
  *
  * The device owns this memory once this call has completed.  The CPU
  * can regain ownership by calling dma_unmap_page().
  */
 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
 	     unsigned long offset, size_t size, enum dma_data_direction dir)
 {
 	dma_addr_t addr;

 	BUG_ON(!valid_dma_direction(dir));

 	addr = __dma_map_page(dev, page, offset, size, dir);
 	debug_dma_map_page(dev, page, offset, size, dir, addr, false);

 	return addr;
 }

 /**
  * dma_unmap_single - unmap a single buffer previously mapped
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @handle: DMA address of buffer
  * @size: size of buffer (same as passed to dma_map_single)
  * @dir: DMA transfer direction (same as passed to dma_map_single)
  *
  * Unmap a single streaming mode DMA translation.  The handle and size
  * must match what was provided in the previous dma_map_single() call.
  * All other usages are undefined.
  *
  * After this call, reads by the CPU to the buffer are guaranteed to see
  * whatever the device wrote there.
  */
 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir)
 {
 	debug_dma_unmap_page(dev, handle, size, dir, true);
 	__dma_unmap_page(dev, handle, size, dir);
 }

 /**
  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @handle: DMA address of buffer
  * @size: size of buffer (same as passed to dma_map_page)
  * @dir: DMA transfer direction (same as passed to dma_map_page)
  *
  * Unmap a page streaming mode DMA translation.  The handle and size
  * must match what was provided in the previous dma_map_page() call.
  * All other usages are undefined.
  *
  * After this call, reads by the CPU to the buffer are guaranteed to see
  * whatever the device wrote there.
  */
 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir)
 {
 	debug_dma_unmap_page(dev, handle, size, dir, false);
 	__dma_unmap_page(dev, handle, size, dir);
 }

 /**
  * dma_sync_single_range_for_cpu
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @handle: DMA address of buffer
  * @offset: offset of region to start sync
  * @size: size of region to sync
  * @dir: DMA transfer direction (same as passed to dma_map_single)
  *
  * Make physical memory consistent for a single streaming mode DMA
  * translation after a transfer.
  *
  * If you perform a dma_map_single() but wish to interrogate the
  * buffer using the cpu, yet do not wish to teardown the PCI dma
  * mapping, you must call this function before doing so.  At the
  * next point you give the PCI dma address back to the card, you
  * must first the perform a dma_sync_for_device, and then the
  * device again owns the buffer.
  */
 static inline void dma_sync_single_range_for_cpu(struct device *dev,
 		dma_addr_t handle, unsigned long offset, size_t size,
 		enum dma_data_direction dir)
 {
 	BUG_ON(!valid_dma_direction(dir));

 	debug_dma_sync_single_for_cpu(dev, handle + offset, size, dir);

 	if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
 		return;

 	__dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
 }

 static inline void dma_sync_single_range_for_device(struct device *dev,
 		dma_addr_t handle, unsigned long offset, size_t size,
 		enum dma_data_direction dir)
 {
 	BUG_ON(!valid_dma_direction(dir));

 	debug_dma_sync_single_for_device(dev, handle + offset, size, dir);

 	if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
 		return;

 	__dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
 }

 static inline void dma_sync_single_for_cpu(struct device *dev,
 		dma_addr_t handle, size_t size, enum dma_data_direction dir)
 {
 	dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
 }

 static inline void dma_sync_single_for_device(struct device *dev,
 		dma_addr_t handle, size_t size, enum dma_data_direction dir)
 {
 	dma_sync_single_range_for_device(dev, handle, 0, size, dir);
 }

 /*
  * The scatter list versions of the above methods.
  */
 extern int dma_map_sg(struct device *, struct scatterlist *, int,
 		enum dma_data_direction);
 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
 		enum dma_data_direction);
 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 		enum dma_data_direction);
 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 		enum dma_data_direction);


 #endif /* __KERNEL__ */
 #endif
	#ifndef ASMARM_DMA_MAPPING_H
	#define ASMARM_DMA_MAPPING_H

	#ifdef __KERNEL__

	#include <linux/mm_types.h>
	#include <linux/scatterlist.h>
	#include <linux/dma-debug.h>

	#include <asm-generic/dma-coherent.h>
	#include <asm/memory.h>

	#ifdef __arch_page_to_dma
	#error Please update to __arch_pfn_to_dma
	#endif

	/*
	* dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
	* functions used internally by the DMA-mapping API to provide DMA
	* addresses. They must not be used by drivers.
	*/
	#ifndef __arch_pfn_to_dma
	static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
	{
	return (dma_addr_t)__pfn_to_bus(pfn);
	}

	static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
	{
	return __bus_to_pfn(addr);
	}

	static inline void dma_to_virt(struct device dev, dma_addr_t addr)
	{
	return (void *)__bus_to_virt(addr);
	}

	static inline dma_addr_t virt_to_dma(struct device dev, void addr)
	{
	return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
	}
	#else
	static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
	{
	return __arch_pfn_to_dma(dev, pfn);
	}

	static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
	{
	return __arch_dma_to_pfn(dev, addr);
	}

	static inline void dma_to_virt(struct device dev, dma_addr_t addr)
	{
	return __arch_dma_to_virt(dev, addr);
	}

	static inline dma_addr_t virt_to_dma(struct device dev, void addr)
	{
	return __arch_virt_to_dma(dev, addr);
	}
	#endif

	/*
	* The DMA API is built upon the notion of "buffer ownership". A buffer
	* is either exclusively owned by the CPU (and therefore may be accessed
	* by it) or exclusively owned by the DMA device. These helper functions
	* represent the transitions between these two ownership states.
	*
	* Note, however, that on later ARMs, this notion does not work due to
	* speculative prefetches. We model our approach on the assumption that
	* the CPU does do speculative prefetches, which means we clean caches
	* before transfers and delay cache invalidation until transfer completion.
	*
	* Private support functions: these are not part of the API and are
	* liable to change. Drivers must not use these.
	*/
	static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size,
	enum dma_data_direction dir)
	{
	extern void ___dma_single_cpu_to_dev(const void *, size_t,
	enum dma_data_direction);

	if (!arch_is_coherent())
	___dma_single_cpu_to_dev(kaddr, size, dir);
	}

	static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size,
	enum dma_data_direction dir)
	{
	extern void ___dma_single_dev_to_cpu(const void *, size_t,
	enum dma_data_direction);

	if (!arch_is_coherent())
	___dma_single_dev_to_cpu(kaddr, size, dir);
	}

	static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
	size_t size, enum dma_data_direction dir)
	{
	extern void ___dma_page_cpu_to_dev(struct page *, unsigned long,
	size_t, enum dma_data_direction);

	if (!arch_is_coherent())
	___dma_page_cpu_to_dev(page, off, size, dir);
	}

	static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
	size_t size, enum dma_data_direction dir)
	{
	extern void ___dma_page_dev_to_cpu(struct page *, unsigned long,
	size_t, enum dma_data_direction);

	if (!arch_is_coherent())
	___dma_page_dev_to_cpu(page, off, size, dir);
	}

	extern int dma_supported(struct device *, u64);
	extern int dma_set_mask(struct device *, u64);

	/*
	* DMA errors are defined by all-bits-set in the DMA address.
	*/
	static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
	{
	return dma_addr == ~0;
	}

	/*
	* Dummy noncoherent implementation. We don't provide a dma_cache_sync
	* function so drivers using this API are highlighted with build warnings.
	*/
	static inline void dma_alloc_noncoherent(struct device dev, size_t size,
	dma_addr_t *handle, gfp_t gfp)
	{
	return NULL;
	}

	static inline void dma_free_noncoherent(struct device *dev, size_t size,
	void *cpu_addr, dma_addr_t handle)
	{
	}

	/**
	* dma_alloc_coherent - allocate consistent memory for DMA
	* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
	* @size: required memory size
	* @handle: bus-specific DMA address
	*
	* Allocate some uncached, unbuffered memory for a device for
	* performing DMA. This function allocates pages, and will
	* return the CPU-viewed address, and sets @handle to be the
	* device-viewed address.
	*/
	extern void dma_alloc_coherent(struct device , size_t, dma_addr_t *, gfp_t);

	/**
	* dma_free_coherent - free memory allocated by dma_alloc_coherent
	* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
	* @size: size of memory originally requested in dma_alloc_coherent
	* @cpu_addr: CPU-view address returned from dma_alloc_coherent
	* @handle: device-view address returned from dma_alloc_coherent
	*
	* Free (and unmap) a DMA buffer previously allocated by
	* dma_alloc_coherent().
	*
	* References to memory and mappings associated with cpu_addr/handle
	* during and after this call executing are illegal.
	*/
	extern void dma_free_coherent(struct device , size_t, void , dma_addr_t);

	/**
	* dma_mmap_coherent - map a coherent DMA allocation into user space
	* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
	* @vma: vm_area_struct describing requested user mapping
	* @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
	* @handle: device-view address returned from dma_alloc_coherent
	* @size: size of memory originally requested in dma_alloc_coherent
	*
	* Map a coherent DMA buffer previously allocated by dma_alloc_coherent
	* into user space. The coherent DMA buffer must not be freed by the
	* driver until the user space mapping has been released.
	*/
	int dma_mmap_coherent(struct device , struct vm_area_struct ,
	void *, dma_addr_t, size_t);


	/**
	* dma_alloc_writecombine - allocate writecombining memory for DMA
	* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
	* @size: required memory size
	* @handle: bus-specific DMA address
	*
	* Allocate some uncached, buffered memory for a device for
	* performing DMA. This function allocates pages, and will
	* return the CPU-viewed address, and sets @handle to be the
	* device-viewed address.
	*/
	extern void dma_alloc_writecombine(struct device , size_t, dma_addr_t *,
	gfp_t);

	#define dma_free_writecombine(dev,size,cpu_addr,handle) \
	dma_free_coherent(dev,size,cpu_addr,handle)

	int dma_mmap_writecombine(struct device , struct vm_area_struct ,
	void *, dma_addr_t, size_t);

	/*
	* This can be called during boot to increase the size of the consistent
	* DMA region above it's default value of 2MB. It must be called before the
	* memory allocator is initialised, i.e. before any core_initcall.
	*/
	extern void __init init_consistent_dma_size(unsigned long size);


	#ifdef CONFIG_DMABOUNCE
	/*
	* For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
	* and utilize bounce buffers as needed to work around limited DMA windows.
	*
	* On the SA-1111, a bug limits DMA to only certain regions of RAM.
	* On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
	* On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
	*
	* The following are helper functions used by the dmabounce subystem
	*
	*/

	/**
	* dmabounce_register_dev
	*
	* @dev: valid struct device pointer
	* @small_buf_size: size of buffers to use with small buffer pool
	* @large_buf_size: size of buffers to use with large buffer pool (can be 0)
	* @needs_bounce_fn: called to determine whether buffer needs bouncing
	*
	* This function should be called by low-level platform code to register
	* a device as requireing DMA buffer bouncing. The function will allocate
	* appropriate DMA pools for the device.
	*/
	extern int dmabounce_register_dev(struct device *, unsigned long,
	unsigned long, int ()(struct device , dma_addr_t, size_t));

	/**
	* dmabounce_unregister_dev
	*
	* @dev: valid struct device pointer
	*
	* This function should be called by low-level platform code when device
	* that was previously registered with dmabounce_register_dev is removed
	* from the system.
	*
	*/
	extern void dmabounce_unregister_dev(struct device *);

	/*
	* The DMA API, implemented by dmabounce.c. See below for descriptions.
	*/
	extern dma_addr_t __dma_map_page(struct device , struct page ,
	unsigned long, size_t, enum dma_data_direction);
	extern void __dma_unmap_page(struct device *, dma_addr_t, size_t,
	enum dma_data_direction);

	/*
	* Private functions
	*/
	int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
	size_t, enum dma_data_direction);
	int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
	size_t, enum dma_data_direction);
	#else
	static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
	unsigned long offset, size_t size, enum dma_data_direction dir)
	{
	return 1;
	}

	static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
	unsigned long offset, size_t size, enum dma_data_direction dir)
	{
	return 1;
	}


	static inline dma_addr_t __dma_map_page(struct device dev, struct page page,
	unsigned long offset, size_t size, enum dma_data_direction dir)
	{
	__dma_page_cpu_to_dev(page, offset, size, dir);
	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
	}

	static inline void __dma_unmap_page(struct device *dev, dma_addr_t handle,
	size_t size, enum dma_data_direction dir)
	{
	__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
	handle & ~PAGE_MASK, size, dir);
	}
	#endif /* CONFIG_DMABOUNCE */

	/**
	* dma_map_single - map a single buffer for streaming DMA
	* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
	* @cpu_addr: CPU direct mapped address of buffer
	* @size: size of buffer to map
	* @dir: DMA transfer direction
	*
	* Ensure that any data held in the cache is appropriately discarded
	* or written back.
	*
	* The device owns this memory once this call has completed. The CPU
	* can regain ownership by calling dma_unmap_single() or
	* dma_sync_single_for_cpu().
	*/
	static inline dma_addr_t dma_map_single(struct device dev, void cpu_addr,
	size_t size, enum dma_data_direction dir)
	{
	unsigned long offset;
	struct page *page;
	dma_addr_t addr;

	BUG_ON(!virt_addr_valid(cpu_addr));
	BUG_ON(!virt_addr_valid(cpu_addr + size - 1));
	BUG_ON(!valid_dma_direction(dir));

	page = virt_to_page(cpu_addr);
	offset = (unsigned long)cpu_addr & ~PAGE_MASK;
	addr = __dma_map_page(dev, page, offset, size, dir);
	debug_dma_map_page(dev, page, offset, size, dir, addr, true);

	return addr;
	}

	/**
	* dma_map_page - map a portion of a page for streaming DMA
	* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
	* @page: page that buffer resides in
	* @offset: offset into page for start of buffer
	* @size: size of buffer to map
	* @dir: DMA transfer direction
	*
	* Ensure that any data held in the cache is appropriately discarded
	* or written back.
	*
	* The device owns this memory once this call has completed. The CPU
	* can regain ownership by calling dma_unmap_page().
	*/
	static inline dma_addr_t dma_map_page(struct device dev, struct page page,
	unsigned long offset, size_t size, enum dma_data_direction dir)
	{
	dma_addr_t addr;

	BUG_ON(!valid_dma_direction(dir));

	addr = __dma_map_page(dev, page, offset, size, dir);
	debug_dma_map_page(dev, page, offset, size, dir, addr, false);

	return addr;
	}

	/**
	* dma_unmap_single - unmap a single buffer previously mapped
	* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
	* @handle: DMA address of buffer
	* @size: size of buffer (same as passed to dma_map_single)
	* @dir: DMA transfer direction (same as passed to dma_map_single)
	*
	* Unmap a single streaming mode DMA translation. The handle and size
	* must match what was provided in the previous dma_map_single() call.
	* All other usages are undefined.
	*
	* After this call, reads by the CPU to the buffer are guaranteed to see
	* whatever the device wrote there.
	*/
	static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
	size_t size, enum dma_data_direction dir)
	{
	debug_dma_unmap_page(dev, handle, size, dir, true);
	__dma_unmap_page(dev, handle, size, dir);
	}

	/**
	* dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
	* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
	* @handle: DMA address of buffer
	* @size: size of buffer (same as passed to dma_map_page)
	* @dir: DMA transfer direction (same as passed to dma_map_page)
	*
	* Unmap a page streaming mode DMA translation. The handle and size
	* must match what was provided in the previous dma_map_page() call.
	* All other usages are undefined.
	*
	* After this call, reads by the CPU to the buffer are guaranteed to see
	* whatever the device wrote there.
	*/
	static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
	size_t size, enum dma_data_direction dir)
	{
	debug_dma_unmap_page(dev, handle, size, dir, false);
	__dma_unmap_page(dev, handle, size, dir);
	}

	/**
	* dma_sync_single_range_for_cpu
	* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
	* @handle: DMA address of buffer
	* @offset: offset of region to start sync
	* @size: size of region to sync
	* @dir: DMA transfer direction (same as passed to dma_map_single)
	*
	* Make physical memory consistent for a single streaming mode DMA
	* translation after a transfer.
	*
	* If you perform a dma_map_single() but wish to interrogate the
	* buffer using the cpu, yet do not wish to teardown the PCI dma
	* mapping, you must call this function before doing so. At the
	* next point you give the PCI dma address back to the card, you
	* must first the perform a dma_sync_for_device, and then the
	* device again owns the buffer.
	*/
	static inline void dma_sync_single_range_for_cpu(struct device *dev,
	dma_addr_t handle, unsigned long offset, size_t size,
	enum dma_data_direction dir)
	{
	BUG_ON(!valid_dma_direction(dir));

	debug_dma_sync_single_for_cpu(dev, handle + offset, size, dir);

	if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
	return;

	__dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
	}

	static inline void dma_sync_single_range_for_device(struct device *dev,
	dma_addr_t handle, unsigned long offset, size_t size,
	enum dma_data_direction dir)
	{
	BUG_ON(!valid_dma_direction(dir));

	debug_dma_sync_single_for_device(dev, handle + offset, size, dir);

	if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
	return;

	__dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
	}

	static inline void dma_sync_single_for_cpu(struct device *dev,
	dma_addr_t handle, size_t size, enum dma_data_direction dir)
	{
	dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
	}

	static inline void dma_sync_single_for_device(struct device *dev,
	dma_addr_t handle, size_t size, enum dma_data_direction dir)
	{
	dma_sync_single_range_for_device(dev, handle, 0, size, dir);
	}

	/*
	* The scatter list versions of the above methods.
	*/
	extern int dma_map_sg(struct device , struct scatterlist , int,
	enum dma_data_direction);
	extern void dma_unmap_sg(struct device , struct scatterlist , int,
	enum dma_data_direction);
	extern void dma_sync_sg_for_cpu(struct device , struct scatterlist , int,
	enum dma_data_direction);
	extern void dma_sync_sg_for_device(struct device , struct scatterlist , int,
	enum dma_data_direction);


	#endif /* __KERNEL__ */
	#endif